1 /* 2 * ng_UI.c 3 */ 4 5 /*- 6 * Copyright (c) 1996-1999 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Julian Elischer <julian@freebsd.org> 39 * 40 * $FreeBSD$ 41 * $Whistle: ng_UI.c,v 1.14 1999/11/01 09:24:51 julian Exp $ 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/errno.h> 47 #include <sys/kernel.h> 48 #include <sys/malloc.h> 49 #include <sys/mbuf.h> 50 #include <sys/errno.h> 51 52 #include <netgraph/ng_message.h> 53 #include <netgraph/netgraph.h> 54 #include <netgraph/ng_UI.h> 55 56 /* 57 * DEFINITIONS 58 */ 59 60 /* Everything, starting with sdlc on has defined UI as 0x03 */ 61 #define HDLC_UI 0x03 62 63 /* Node private data */ 64 struct ng_UI_private { 65 hook_p downlink; 66 hook_p uplink; 67 }; 68 typedef struct ng_UI_private *priv_p; 69 70 /* Netgraph node methods */ 71 static ng_constructor_t ng_UI_constructor; 72 static ng_rcvmsg_t ng_UI_rcvmsg; 73 static ng_shutdown_t ng_UI_shutdown; 74 static ng_newhook_t ng_UI_newhook; 75 static ng_rcvdata_t ng_UI_rcvdata; 76 static ng_disconnect_t ng_UI_disconnect; 77 78 /* Node type descriptor */ 79 static struct ng_type typestruct = { 80 .version = NG_ABI_VERSION, 81 .name = NG_UI_NODE_TYPE, 82 .constructor = ng_UI_constructor, 83 .rcvmsg = ng_UI_rcvmsg, 84 .shutdown = ng_UI_shutdown, 85 .newhook = ng_UI_newhook, 86 .rcvdata = ng_UI_rcvdata, 87 .disconnect = ng_UI_disconnect, 88 }; 89 NETGRAPH_INIT(UI, &typestruct); 90 91 /************************************************************************ 92 NETGRAPH NODE STUFF 93 ************************************************************************/ 94 95 /* 96 * Create a newborn node. We start with an implicit reference. 97 */ 98 99 static int 100 ng_UI_constructor(node_p node) 101 { 102 priv_p priv; 103 104 /* Allocate private structure */ 105 priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO); 106 NG_NODE_SET_PRIVATE(node, priv); 107 return (0); 108 } 109 110 /* 111 * Give our ok for a hook to be added 112 */ 113 static int 114 ng_UI_newhook(node_p node, hook_p hook, const char *name) 115 { 116 const priv_p priv = NG_NODE_PRIVATE(node); 117 118 if (!strcmp(name, NG_UI_HOOK_DOWNSTREAM)) { 119 if (priv->downlink) 120 return (EISCONN); 121 priv->downlink = hook; 122 } else if (!strcmp(name, NG_UI_HOOK_UPSTREAM)) { 123 if (priv->uplink) 124 return (EISCONN); 125 priv->uplink = hook; 126 } else 127 return (EINVAL); 128 return (0); 129 } 130 131 /* 132 * Receive a control message 133 */ 134 static int 135 ng_UI_rcvmsg(node_p node, item_p item, hook_p lasthook) 136 { 137 int error; 138 const priv_p priv = NG_NODE_PRIVATE(node); 139 struct ng_mesg *msg; 140 141 msg = NGI_MSG(item); /* only peeking */ 142 if ((msg->header.typecookie == NGM_FLOW_COOKIE) && lasthook) { 143 if (lasthook == priv->downlink) { 144 if (priv->uplink) { 145 NG_FWD_ITEM_HOOK(error, item, priv->uplink); 146 return (error); 147 } 148 } else { 149 if (priv->downlink) { 150 NG_FWD_ITEM_HOOK(error, item, priv->downlink); 151 return (error); 152 } 153 } 154 } 155 156 NG_FREE_ITEM(item); 157 return (EINVAL); 158 } 159 160 #define MAX_ENCAPS_HDR 1 161 #define ERROUT(x) do { error = (x); goto done; } while (0) 162 163 /* 164 * Receive a data frame 165 */ 166 static int 167 ng_UI_rcvdata(hook_p hook, item_p item) 168 { 169 const node_p node = NG_HOOK_NODE(hook); 170 const priv_p priv = NG_NODE_PRIVATE(node); 171 struct mbuf *m; 172 int error = 0; 173 174 NGI_GET_M(item, m); 175 if (hook == priv->downlink) { 176 u_char *start, *ptr; 177 178 if (m->m_len < MAX_ENCAPS_HDR 179 && !(m = m_pullup(m, MAX_ENCAPS_HDR))) 180 ERROUT(ENOBUFS); 181 ptr = start = mtod(m, u_char *); 182 183 /* Must be UI frame */ 184 if (*ptr++ != HDLC_UI) 185 ERROUT(0); 186 187 m_adj(m, ptr - start); 188 NG_FWD_NEW_DATA(error, item, priv->uplink, m); /* m -> NULL */ 189 } else if (hook == priv->uplink) { 190 M_PREPEND(m, 1, M_NOWAIT); /* Prepend IP NLPID */ 191 if (!m) 192 ERROUT(ENOBUFS); 193 mtod(m, u_char *)[0] = HDLC_UI; 194 NG_FWD_NEW_DATA(error, item, priv->downlink, m); /* m -> NULL */ 195 } else 196 panic("%s", __func__); 197 198 done: 199 NG_FREE_M(m); /* does nothing if m == NULL */ 200 if (item) 201 NG_FREE_ITEM(item); 202 return (error); 203 } 204 205 /* 206 * Shutdown node 207 */ 208 static int 209 ng_UI_shutdown(node_p node) 210 { 211 const priv_p priv = NG_NODE_PRIVATE(node); 212 213 /* Take down netgraph node */ 214 free(priv, M_NETGRAPH); 215 NG_NODE_SET_PRIVATE(node, NULL); 216 NG_NODE_UNREF(node); 217 return (0); 218 } 219 220 /* 221 * Hook disconnection 222 */ 223 static int 224 ng_UI_disconnect(hook_p hook) 225 { 226 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 227 228 if (hook == priv->downlink) 229 priv->downlink = NULL; 230 else if (hook == priv->uplink) 231 priv->uplink = NULL; 232 else 233 panic("%s", __func__); 234 /* 235 * If we are not already shutting down, 236 * and we have no more hooks, then DO shut down. 237 */ 238 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 239 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 240 ng_rmnode_self(NG_HOOK_NODE(hook)); 241 } 242 return (0); 243 } 244